Does the age of a crane prevent it from having a collision avoidance system installed?

Jon Walters, Magnetek trainer and safety webinar presenter, answers:

No. The age of a crane has no impact on whether a collision avoidance system can be incorporated, but there is some basic information that should be considered to ensure it is applied correctly.

Control Voltage

Confirm the necessary control voltage needed so the collision avoidance system can be matched to the existing control voltage. This ensures major changes will not be needed to existing crane control logic. Magnetek’s collision avoidance systems are designed to operate with control voltages of 12-240 VAC or VDC.

Type of Existing Crane Control

Is it a contractor control, static stepless control or a variable frequency drive? Determining the existing control scheme defines how the output(s) from the collision avoidance system will be incorporated into the existing control logic. Older cranes may be operating with contactor controls, but still permit the installation of collision avoidance systems.

Type and Number of Crane Motions:

What crane motions will collision avoidance be applied to? Motions may be:

Bridge to obstruction (such as a wall or no-go area)

Bridge to bridge

Trolley motion to end of travel on bridge

Trolley to trolley

The number of motions, along with any “no fly” zones, will determine the number of collision avoidance systems needed.

Distance

The distance at which a collision avoidance system will “trigger” is determined based on the distances and speeds of the traverse motions in accordance with what is deemed safe for a slowdown and stop function.

The above factors will help determine the configuration of a collision avoidance system that can be added to your crane, which, again, may be implemented regardless of crane age.

Al, a CMCO distributor salesman, trainer and recent safety webinar attendee, asked the following question about applying a radio remote control:

Does the age of a crane prevent it from having a radio remote control installed?

Jon Walters, Magnetek trainer and safety webinar presenter, answers:

No, the age of a crane has no impact on whether a radio remote control can be incorporated. There is some basic information that should be considered to determine the proper style of radio remote control and ensure it is applied correctly:

Control voltage:

Confirming the radio receiver voltage can be matched to the existing control voltage ensures no significant alterations are required to the crane.

In addition to standard AC control voltages, all Magnetek radio remote controls are adaptable to the most common DC voltage control voltages – 12/24/48/250.

Type of existing crane control:

Is it a contactor control, static stepless control, or a variable frequency drive? Determining the existing control scheme allows for the selection of the optimal radio control product. Older cranes may be operating with contactor controls, but still permit the installation of radio remote control.

The number of motions on the crane:

Is it a basic three-motion (bridge/trolley/hoist) crane or does it perform more or fewer motions? This will dictate how many crane motion outputs are needed on the receiver.

Transmission distance:

Is there a range limitation or is an extended range needed? The transmission distance is based on the crane application. For example, in situations where the transported material is very delicate, precise positioning is critical. This requires the crane operator or spotters to be in close proximity to the load and range limitation would be advisable. If the crane is operating in a long runway with no obstructions and no areas are deemed unsafe, then an extended range may be considered.

The above factors will help determine the style of radio remote control you can add to your crane, which may be implemented regardless of crane age.

I sat down with subject matter expert and Magnetek controls product manager, Casey Cummins, to discuss the benefits and features of crane collision avoidance systems.

Q: What is a crane collision avoidance system?

Casey: Collision avoidance systems are electronic devices that can be installed on your crane to help prevent accidents before they happen, protecting people, the facility, the end product and the crane itself. Collision avoidance systems are typically used in overhead material handling applications where multiple cranes are employed on a single runway, as well as where a single crane is in use. They are designed to prevent crane-to-crane and crane-to-end stop collisions, increasing operator safety and reducing system maintenance.

Q: Is the demand for collision avoidance systems growing?

Casey: Collision avoidance systems are increasingly being added to material handling systems as the demand for products that improve workplace safety grows. Collision avoidance systems intervene, when necessary, to prevent accidents, and are a reliable means of preventing human error, helping to make the workplace safer and reducing maintenance costs.

Q: Are there specific standards that require this type of system?

Casey: Collision avoidance systems are designed to prevent unintentional contact between cranes or other equipment. Although there are no specific requirements in today’s general duty crane standards to provide collision avoidance, CMAA states that all collision avoidance requirements shall be specified by the owner or purchaser of the crane. End-of-travel collision avoidance should be designed to prevent unintentional contact of the crane or trolley with mechanical end stops or other equipment. Collision avoidance should reduce speed and/or stop the travel motion prior to impact.

Q: What type of collision avoidance systems does Magnetek offer?

Casey: Magnetek offers three collision avoidance systems which can be applied to all types of overhead cranes or monorails with adjustable frequency drives, soft starters or contactor controls. Multiple configurations are available so customers can choose the exact functionality, size and style to fit their application needs. All Magnetek’s collision avoidance systems are rated IP65 or better for indoor or outdoor applications. The collision avoidance systems are “fail-safe,” which means that if the sensor loses power, motion of the crane would be stopped and restricted.

Casey: Magnetek’s ReFlx 45 product uses a modulated visible LED light signal, while the ReFlx 120 product uses an infrared light signal. These light signals are transmitted at a reflective target and a receiver senses the reflected signal from that target. The information is then processed and the appropriate relay will open, providing for slow down or stoppage of motion. Depending on the device selected, ReFlx has a detection range between 3 and 120 feet.

Magnetek’s LaserGuard2 collision avoidance product is the most technologically advanced system available, using self-monitoring optical lasers to check a crane’s position. Its multi-distance detection feature is flexible enough to manage crane-to-crane and wall-to-crane operations. The configurable set-point range of this laser-based system (from 8 inches to 150 feet) provides the ability to monitor distances between cranes, trolleys and monorail carriers, and prevent collision between this equipment. Laser-based systems offer the most precise positioning and are particularly useful in an automated environment.

LaserGuard2 Collision Avoidance System

Q: What trends in the market do you see?

Casey: The industry is moving toward remote diagnostics and monitoring, which will allow crane operators to monitor the crane on their mobile phone or tablet from the ground or anywhere in the world. Magnetek offers remote diagnostics with its engineered solutions.

When working as a crane operator in a facility or at a jobsite, especially those with lots of traffic, it is crucial to understand and use crane operator hand signals. As required by OSHA 1926.1400 Cranes and Derricks, these individuals, or signal persons, must know all signals for mobile, tower and overhead cranes and must have a basic understanding of crane operation.

Charts identifying these hand signals must be posted on equipment or noticeably near hoisting operations. If modifications are made to any signals, they must be agreed upon by the crane operator, lift director and signal person and cannot conflict with the standard signals.

Identifying the Signal Person

The lift director at the jobsite has to appoint a qualified signal person before the lift. During crane operation, only one person can give signals, unless it’s for an emergency stop – then anyone on the jobsite can give the signal. Once the qualified signal person is identified, the signal person and the crane operator must identify each other prior to giving any signals.

Signaling the Crane Operator During the Lift

During crane operation, signals should be continuous. If at any time a signal is not understood, is not clear, is disrupted or is not audible, the crane operator must stop movement and not give a response.
When giving signals, all signs should be from the operator’s perspective. So, for example, to designate swing left, the signal person would extend their right arm so the operator would swing left.

In addition to hand signals, voice signals can be used. Voice signals must have three elements:

It’s important to note that when communicating with more than one crane, a procedure or system must be used to identify which crane that the signal is for. This helps avoid confusion on the part of the crane operator, allowing them to easily identify which crane should respond.

Moving the Crane

When the operator moves the crane into position, the following horn or audible sounds shall be used:

Stop: One short audible signal

Go Ahead: Two short audible signals

Back Up: Three short audible signals

These sounds are required to ensure that those not directly involved in controlling or working with the crane are aware of the crane’s movement in the job site.

To see a full list of all crane operator hand signals, including explanations and diagrams, click here.

Variable frequency drives, or VFDs, are a type of AC motor controller that drive an electric motor by varying the frequency and voltage supplied to it. VFDs are also commonly known as variable speed or adjustable speed drives, AC drives, micro-drives or inverters – depending on the industry or application.

In the material handling industry, variable frequency drive controls are often used in electric hoists as well as in overhead cranes and lifting systems. Drives are designed around a microprocessor, which allows for the creation of programmable functions for specific applications.

So, what are the benefits of using a VFD to control your hoist or crane?

2. Improved Load Control: Positioning a load using a single-speed hoist may cause shock loading or load swings. A VFD allows for smooth operation by gradually slowing down a load. Variable frequency drives also allow for smooth acceleration to prevent load swings in the traverse motions.

3. Duty Cycles: CMAA Class A-F. A VFD is concisely matched with a braking resistor, depending on the duty cycle of the motion. A regenerative drive may also be used, which is not dependent on duty cycle.

4. Efficiency: A VFD will only consume the power that’s needed, thus saving energy compared to contactors and soft-starters.

5. Increased Hoist Life: Some variable frequency drives provide thermal overload and overcurrent protection for the hoist motor, prolonging its life. VFDs also utilize a ramp-down-to-stop method of braking rather than using brake shoes to slow down. The brake is only used for parking and emergency situations, which prolongs brake life.

6. Regenerative Energy: Deceleration and lowering of a hoist creates regenerative energy produced by the motor. This energy can be transformed into heat using a braking resistor or conditioned and send back to the source, thus netting energy savings. An AC regenerative drive will redistribute that energy, which would otherwise be wasted when converted to heat with a braking resistor.

7. Digital Diagnostics: Aid in maintenance and troubleshooting on the machine or remotely.

Magnetek VFDs are designed for crane and hoist applications with various performance and safety features. A few of these features include:

1. Safe Torque Off: Provides a redundant hardware safety circuit that guarantees motor and brake power are removed when an E-STOP switch or safety controller opens the drive input, eliminating the need for external disconnects.

2. Torque Proving: The motor is pre-torqued to guarantee that the load can be held before opening the brake.

3. Load Check: Continuously checks for hoist overloads and prevents the hoist from lifting when an overload condition is detected.

4. Brake Checks: Monitors the opening and closing of a brake to ensure that it is safe and healthy.

During the hundreds of classes Columbus McKinnon’s training team has conducted over the years, there are a variety of questions that arise regarding the use, maintenance and inspection of overhead cranes and hoists. So, I wanted to take this opportunity to outline seven of the most common concerns, myths and misconceptions we’ve received from crane and hoist operators and technicians during our classes.

1. Question: Do monorails need to be labeled with their rated load?

Answer: According to ASME B30.11, rated load markings are not required on monorails but are recommended. Before marking the monorail, a qualified person must determine the rated load on the monorail beam. Once the monorail is marked, the rating should be legible from the ground floor. ASME’s recommendation also applies to marking the rated loads of hoists on the monorail. For more information on hoist marking guidelines, see ASME B30.16.

2. Question: Can rated loads for hoists and trolleys be different from the crane’s rated load?

Answer: The short answer to your question is “yes.” However, ASME B30.16 stipulates that when a system is comprised of components with different rated capacities, the rated load of the “system” shall be based on the lowest rated individual component.
System is defined as the combination of Monorail, Hoist and Trolley in the case of a Monorail and Crane; Hoist and Trolley in the case of an Underhung Crane.

ASME B30.16-1.3.2 states that the supporting structure, including trolleys, monorail, or crane, shall be designed to withstand the loads and forces imposed by the hoist for the rated load.

3. Question: Are yearly load tests required on a hoist and crane?

Answer: There is no specific time period during which load tests must be performed once the initial installation is inspected and load tested. Some states require operators to load test hoists and cranes every four years, but, in most cases, if the hoist is not altered, repaired or modified, it can remain in service indefinitely without a load test being required.

Answer: This depends on the type of crane. OSHA regulation 1910.179 applies to top-running overhead and gantry cranes with top-running trolley hoists. For these types of cranes, monthly inspections of the hoist’s chain, wire rope and hooks are required with a recorded certification. This certification record must include the signature of the person who performed the inspection and the identifier of the chain, wire and hook that was inspected. If a hoist and trolley are underhung, frequent inspections are required, but written documentation is not.

5. Question: Do you have to be certified to inspect and repair hoists and cranes?

Answer: According to ASME standards, you must be a “qualified person” to inspect and repair cranes and hoists. A “qualified person” is a person who, by possession of a recognized degree or certificate of professional standing, or who, by extensive knowledge, training and experience, has successfully demonstrated the ability to solve or resolve problems relating to the subject matter and work. These individuals do not have to be professional engineers.

6. Question: Do you need to disassemble hoists for yearly inspections?

Answer: Hoist disassembly is not always required for yearly inspections. What is found during the inspection typically determines how far you need to break down the hoist. Be sure to reference the manufacturer’s OEM manual when disassembling any hoist.

7. Question: Do chain slings require latches on hooks?

Answer: According to OSHA 1910.184 and ASME B30.9, slings do not require latches on the hooks, unlike hoist and crane hooks where latches are required unless they constitute a hazard.

To learn more, check out our Safety Webinar covering these same questions. I hope you find this information useful when using, repairing or inspecting overhead hoists and cranes.

“On my overhead crane, the rail to flange contact is opposite end-to-end of the end truck. On one end truck, the drive wheel to the flange is on the inside and on the other wheel, the contact is on the outside. What are your recommendations for dealing with these skewing issues in this situation?”

Columbus McKinnon has expanded its comprehensive offering of product and safety training to include NCCCO written and practical certification exams for Overhead Crane Operator Training. The first class will be held November 11-13 at our training center in Tonawanda, N.Y.

Columbus McKinnon’s Overhead Crane Operator Training class is comprised of classroom and hands-on training designed to educate students on OSHA, CMAA, ANSI/ASME B30, and ANSI/ASME P30 regulations as they apply to hoist and crane operators. The class also covers basic rigging safety, proper lifting practices and pre-operational inspection requirements. Now, students can choose to continue their education with NCCCO (National Commission for the Certification of Crane Operators) certification. Earning this certification requires students to take a written exam as well as a practical, hands-on examination. To sign up for the course, visit the CMCO Training website.

Continuing education is very important for crane and hoist operators. By offering NCCCO Overhead Crane Operator Certification, we can help ensure students understand how to properly operate a crane and verify through nationally recognized testing that the student is competent in the course material.

As part of the accreditation process, Columbus McKinnon’s test course materials and test site area at the company’s Niagara Training Center were audited and approved by an NCCCO representative. CMCO instructors also successfully completed written and practical exams administered by the commission.

In addition to Overhead Crane Operator Training, Columbus McKinnon offers a comprehensive range of programs and seminars conducted at venues across North America to promote the safe and proper use of rigging and overhead lifting equipment. Courses include topics such as: hoist maintenance, crane and hoist inspection, Crane Institute of America Certification (CIC) for basic and advanced rigging, rigging gear inspection, and load securement.

For a full list of Columbus McKinnon’s training programs, visit our training website.

Columbus McKinnon fully endorses the national certification program offered by the National Commission for the Certification of Crane Operators (NCCCO).

“I received a call from a customer for whom I had conducted an inspection. The customer stated they received an OSHA reprimand for not having monthly inspections on their cranes. They have 2 top-running bridge underhung trolley-type cranes. OSHA referenced 1910.179 J2IV and 1910.179 B1 as the violations.

In the book I have, 1910.179 B1 states that ‘this section applies to overhead and gantry cranes, including semi gantry, cantilever gantry, wall cranes, storage bridge cranes, and the others having the same fundamental characteristics. These cranes are grouped together because they all have trolleys and similar travel characteristics.’

Are the references for the reprimand accurate?”

Tom answers:

Some confusion exists among crane and hoist owners, users and service providers regarding crane configurations and the application of Federal OSHA 1910.179 regulations. Some of this confusion may be caused by the first definition in 1910.179 – (a)(1): “A “crane” is a machine for lifting and lowering a load and moving it horizontally…” Because all overhead crane configurations fit this definition to one degree or another, we tend to lump them together and assume that all are subject to these regulations. This is not the case. I wrote an article on the subject entitled “Does OSHA 1910.179 apply?” To read the full article, go here.

A second resource I want to share with you consists of two OSHA interpretations:

Each interpretation makes it quite clear that OSHA 1910.179 does not apply to the crane types you describe. For OSHA to prevail on a General Duty Clause, which they have not cited, they would have to prove or establish risk of serious injury or death. If the operators are doing proper daily pre-operational inspections, or even inspections once per month, they are covered. These “Frequent Inspections” do not have to be documented. (ASME B30.17 & B30.16.)

There is some confusion in the industry regarding crane configurations and the application of OSHA regulations. In a recent article in Industrial Lift & Hoist Magazine, Tom Reardon, one of Columbus McKinnon’s training managers, discusses the issue and provides clarification for crane users.

OSHA 1910.179(a)(1) states that “A ‘crane’ is a machine for lifting and lowering a load or moving it horizontally…” As most overhead cranes can fit into this description, they tend to get grouped together and are assumed to be subject to OSHA’s regulations. This is not the case.

OSHA 1910.179(b)(1) defines the types of cranes that fall under its regulations –these regulations do not apply to underhung cranes, overhead hoists or monorails, which are covered by ANSI B30.11 and ANSI B30.16. As a general rule, if both the crane bridge and trolley hoist travel on top of a rail or equivalent, the crane is subject to OSHA 1910.179 regulations. If any load-bearing member of a crane or monorail travels on an internal or external lower flange or equivalent, it is not subject to OSHA regulations.

Even though these types of cranes are not regulated by OSHA 1910.179, ASME and ANSI both have standards regarding the construction, installation, maintenance, inspection and safety of these cranes. OSHA may use the standards set forth by organizations like ANSI and ASME to regulate these cranes under its general duty clause. OSHA will issue a General Duty Citation for serious circumstances where employees are exposed to hazards that present a substantial probability of death or serious injury.

Therefore, when using cranes, it is important to understand the regulations your specific crane falls under and the steps you need to take to ensure your employees are safe and your crane is in proper working order. To read Tom’s full article regarding this topic, visit ILH online.